package com.syzg.base.web.captcha;

import java.io.IOException;    
import javax.servlet.ServletException;    
import javax.servlet.http.HttpServlet;    
import javax.servlet.http.HttpServletRequest;    
import javax.servlet.http.HttpServletResponse;    
import javax.servlet.http.HttpSession;
import java.util.*;    
import java.awt.*;    
import java.awt.image.*;    
    
import javax.imageio.*;    
/** 
 *  
 * @author JH 
 * 
 */  
public class GetCaptcha extends HttpServlet {    
	private static final long serialVersionUID = 2502674987419200340L;

    public GetCaptcha() {
    }

    private Color getRandColor(int fc, int bc) {
        Random random = new Random();
        if(fc > 255)
            fc = 255;
        if(bc > 255)
            bc = 255;
        int r = fc + random.nextInt(bc - fc);
        int g = fc + random.nextInt(bc - fc);
        int b = fc + random.nextInt(bc - fc);
        return new Color(r, g, b);
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
        doGet(request, response);
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
        response.setHeader("Cache-Control", "no-store");
        response.setHeader("Pragma", "no-cache");
        response.setDateHeader("Expires", 0L);
        int width = 70;
        int height = 32;
        BufferedImage image = new BufferedImage(width, height, 1);
        Graphics g = image.getGraphics();
        Random random = new Random();
        g.setColor(getRandColor(200, 250));
        g.fillRect(0, 0, width, height);
        g.setFont(new Font("\u5B8B\u4F53", 1, 22));
        g.setColor(getRandColor(160, 200));
        for(int i = 0; i < 155; i++)
        {
            int x = random.nextInt(width);
            int y = random.nextInt(height);
            int xl = random.nextInt(12);
            int yl = random.nextInt(12);
            g.drawLine(x, y, x + xl, y + yl);
        }

        String sRand = "";
        for(int i = 0; i < 4; i++)
        {
            String rand = String.valueOf(random.nextInt(10));
            sRand = (new StringBuilder(String.valueOf(sRand))).append(rand).toString();
            g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
            g.drawString(rand, 15 * i + 10, 20);
        }

        HttpSession session = request.getSession();
        session.setAttribute("VERIFY_CODE", sRand);
        g.dispose();
        ImageIO.write(image, "JPEG", response.getOutputStream());
    }
    
}   